(1) Field of the Invention
One aspect of this disclosure relates to tooling and methods for molding or replicating leather samples for inspection, selecting and later using those samples in applications such as automobile interiors with leather surfaces that are laminated or have a loose grain appearance.
(2) Description of Related Art
In the leather business, a leather supplier is often asked to replicate natural markings that occur on leather hides. Such markings may be for example a scar, a scratch, an insect bite, or a loose break, which is a condition that leather hides show to accommodate growth in the bovine animal. These natural markings are common in the leather business and are hallmarks of leather authenticity.
Not incorporating natural marks into products that use leather is cost-prohibitive. Because of the need to use natural markings, every automotive original equipment manufacturer has a different allowance for what scars or natural markings can be visible in a seat for example or in another automotive component. With leather seats, only natural markings (that occurred during the lifetime of the animal) are allowed. These markings differ from defects or artifacts created in a manufacturing process.
In the past, leather suppliers would have to replicate a scar to guide what is, and is not allowable as defined by each OEM by: (1) looking for a perfect scar; (2) getting the OEM to approve it, and then (3) trying to find reasonable copies of that scar in nature from potentially hundreds of hides and samples that were to be cut repeatedly.
With the diversification of the supply chains, particularly since the recession of 2007, the need for more and more copies of these replicates has grown exponentially. In the past, the supplier would have had to make about 3 sample inspection books; however, now a supplier might be required to provide 35-100 books of each acceptable natural mark and natural marking category for a global automotive program. So, the process of having to replicate samples and/or find that exact scar from a hide in mass production is increasingly difficult and is in fact often infeasible or may produce variable results.
The former process for creating replicates versus finding a live scar from hides cut in mass production of one scar often proceeds as follows: if the leather supplier had a scar that the OEM specified that it wanted as many copies of it as possible, traditional practices involved making a “laminated split” or “laminated top grain”. To do this, the conventional process was to make a silicone copy (mold) of that scar, spray the silicone mold with a thin layer of finish and then, with an adhesive, adhere the finish to a piece of split leather.
One problem with such practices is that replication of the actual defect at the onset of production is not one-to-one. A replicate of a scar could be far less severe or an area of hide damage known as “mange” could be more severe than what the OEM originally approved.
Another problem with conventional approaches is that the silicone wears out over time. Therefore, a scar that may be emulated perfectly at the beginning of the replication cycle may become less aggressive over time, depending on the required number of replicates. Mold wear is not reliably predictable. Recreation of a mold using the original leather sample is inaccurate as the silicone flattens the leather. This translates into an adverse fiscal impact for leather suppliers. For example, six inches of leather lost over a hide can translate into $6-10 million dollars very quickly. The impact of not being able to use the original severity of the natural marking could be extremely high.
In some circumstances, PVC or vinyl can replicate leather purses, for example. One way to do this is to replicate an original design such an embroidered flower and create a hard tool nickel mold. A mold maker such as Weber Mfg. (see, e.g., www.webermfg.ca, incorporated by reference) for example uses nickel plates to mold an item such as a fiberglass door, instrument panels or virtually any product that could be replicated with a molded substrate. Thus, the mold maker creates hard tooled molds to replicate a component or part of pattern. For example, a customer may want to create fiberglass doors that look like real wood. The mold maker then makes a mold that the fiberglass company could use to make these doors. Another example is the preparation of a nickel mold of a leather wrapped instrument panel. An instrument panel supplier may use a nickel mold to make plastic replicates of the original leather panels.
The automotive industry uses several types and amounts of leather. It has been reported that about 30 percent of cars sold in North America have leather interiors.
http://www.nytimes.com/2003/05/30/travel/driving-rolls-royce-or-hyundai-leather-makes-the-car.html. In the mass production of vehicles with leather surfaces there is a need for molded samples that accurately reflect the appearance and texture of the product.
One way to classify a leather surface is to characterize it as a Level 1-5 surface. The higher the number, the higher is the graininess or looseness.
Leather is also characterized in terms of its
a. Quality—grain (natural patterns and blemishes on the hide; full-grain is the most natural and least processed; top grain is from the hide's outer layer and is often sanded);
b. Type—for example, nappa tends to be soft and supple, saddle is stiffer, and nubuck is like suede;
c. Source—desirable is the natural hide of cattle that are 2-3 years old; older hides may be scarred and more rigid;
d. Color & finish—for example, aniline dyed (transparent dyes permeate the leather without significantly altering its appearance); surface coating (opaque sprays may hide imperfections of less expensive leather); saddlery (grain, texture and scarring are emphasized to imbue the leather with a rougher appearance and feel).
One supplier is Eagle Ottawa in Rochester Hills, Mich., which processes cattle hides for automobile manufacturers. Such suppliers process hides to meet the automakers' specifications.
Before choosing a leather for mass production, the OEM wants to inspect a representative sample of what the product will look and feel like. In the past, the task of loose grain sampling was done by the tedious sorting of hides to find the desired appearance.
Conventional approaches include scanning and making a plastic replication, perhaps in a half pipe format by 3-D printing. But such approaches do not address the appearance of loose grain on the leather. Even the replication process of creating embossing plates is not as consistent or precise in emulating natural markings.
Among the art considered in preparing this patent application are U.S. Pat. Nos. 4,294,650; 3,298,851; 5,750,160; DE 19851117; DE 10119494; CN 2028088220.
Such mold makers make a nickel mold of whatever the customer wants to replicate. Accuracy of such molds is due in part to a process of ‘growing’ the nickel plate one atom at a time. Their process includes making a silicone negative of the sample, then a nickel plate.